Mattress for movable bed

ABSTRACT

A mattress for a movable bed, laid on a floor portion of the movable bed whose bed face is deformable. A fixing element that is the floor portion is provided on a mattress surface opposite the floor portion. The movable bed may be constructed such that meshes are formed on a surface of the floor portion, and that the fixing element is fitted in gaps of the meshes to fix the mattress.

TECHNICAL FIELD

The present invention relates to a mattress designed to be laid on anadjustable bed used for nursing care.

BACKGROUND ART

In order to prevent the occurrence of decubitus ulcers, more commonlyknown as bedsores, adjustable beds used as turning beds and the likeoperate to assist postural change of care recipients. The posturalchange is generally achieved by inclining a part, or the entire mattressof the beds on which care recipients are lying so as to turn the carerecipients in the direction of inclination (refer to Japanese Laid-OpenPatent Application Publication No. H06-14824). The majority of thesetypes of beds employ a mechanism that tilts the mattress surface from aflat position across the width direction of the mattress in order toassist the postural change.

However, when such an adjustable bed operates, it is sometimes the casethat a mattress laid on the bed is displaced, and thereby the carerecipient on the mattress may be shifted from the proper position. Thiscauses an interruption to the normal operations of adjustable beds. Sucha problem also leaves room for improvement in terms of safety for thecare recipients.

DISCLOSURE OF THE INVENTION

In order to solve the problem described above, the present invention isa mattress to be laid on a platform of an adjustable bed having atransformable bed surface. Here, a fixture that engages with theplatform to secure the mattress is disposed on a surface of the mattressfacing the platform.

This structure prevents displacement of the mattress from the bedsurface, which may occur when the adjustable bed is driven.Consequently, a care recipient in a recumbent position on the bed isable to safely start the postural change from the proper position. Inaddition, a good, sound sleep is guaranteed by this structure.

To be more specific, with the mattress of the present invention, a meshmay be formed on a front face of the platform, and the fixture securesthe mattress by tightly fitting into one or more interstices of themesh.

Here, the fixture may be detachable from the platform. This structure isdesirable since it facilitates the mattress replacement and themaintenance of the adjustable bed.

The fixture may be disposed, on the surface of the mattress, in a partof the mattress corresponding to a lower back region of a user lying onthe mattress. This structure is desirable since it facilitatesstretching the mattress when the adjustable bed is driven.

An example of adjustable beds applying the present invention includes:the platform of which the front face is flexible; a flex mechanismoperable to flex the platform to form a flexion position that includesat least one of a sitting-up position and a knee break; and a tiltmechanism operable to tilt the front face laterally. Here, both the flexmechanism and the tilt mechanism are operable with the other mechanismin operating condition.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an adjustable bed in a first embodiment;

FIGS. 2A-2C are partial cross-sectional views in a vicinity of a bedframe and an adjustable stage;

FIG. 3 is a schematic plan view of the adjustable bed;

FIG. 4 is a perspective view showing a structure of a fixed stage;

FIG. 5 is a perspective view of the adjustable bed (with the left-sidemembers raised);

FIG. 6 is a perspective view of the adjustable bed (in a flexionposition);

FIG. 7 is a perspective view of the adjustable bed (tilted laterally tothe left);

FIGS. 8A-8D are longitudinal schematic views of the adjustable bed andthe bed frame;

FIG. 9 is a structure diagram illustrating the adjustable bed having ameshed surface and a mattress having a fixture;

FIG. 10A shows a structure of the mattress fixture and FIGS. 10B-10C arediagrams illustrating a behavior of the mattress when the adjustable bedis driven;

FIGS. 11A and 11B are perspective views of a variation of the adjustablebed; and

FIGS. 12A-12F are perspective views of another variation of theadjustable bed.

BEST MODE FOR CARRYING OUT THE INVENTION 1. FIRST EMBODIMENT

1.1 Structure of Adjustable Bed

FIG. 1 is a perspective view illustrating a structure of an adjustablebed 2 according to a first embodiment of the present invention.

The adjustable bed 2 is constituted such that a bed frame 10 is disposedon an adjustable stage 20 placed on a fixed stage 30.

The bed frame 10 includes a coupled platform 11 a-11 d, which is formedby dividing a surface part (i.e. upper surface of the bed) into foursections corresponding to the back, hip, upper-leg, and lower-legregions of a care recipient's body lying on the bed, and coupling thesesections together so as to be freely adjustable. In the coupled platform11 a-11 d, an upper-body member 11 a, a lower-back member 11 b, anupper-leg member 11 c, and a lower-leg member 11 d are each coupled inthe given order.

The lower-back member 11 b is fixed directly onto the adjustable stage20 by welding, for example, thus preventing the bed frame 10 from beingdisengaged from the adjustable stage 20. Side members 12Ra-12Rd and12La-12Ld for supporting the care recipient's body from the sides arecoupled to the platform 11 a-11 d on the right and left, respectively.The upper-body member 11 a and upper-leg member 11 c of the bed frame 10are respectively coupled, via L-shaped couplers 211 and 212, to theshafts of direct-acting actuators M1 and M2 (see FIG. 3 showing a planview of the bed) disposed on a center beam 21A of the adjustable stage20. Herewith, the actuators M1 and M2 are able to transform the bedframe 10 so that the care recipient is placed in a flexion position (seeFIG. 6 showing a bed form; FIG. 8B showing a side view of the bed).

A wire mesh is in fact placed over the surface of the coupled platform11 a-11 d and side members 12Ra-12Rd and 12La-12Ld of the bed frame 10.However, here, this wire mesh has been omitted from the drawing as wellas the following drawings in order to illustrate the structure of thebed with clarity. Consequently, these drawings depict only the frames ofthe coupled platform 11 a-11 d and side members 12Rd-12Rd and 12La-12Ld.In the present invention, however, the coupled platform and side membersare not confined to having the wire-mesh surface construction, and mayalternatively be composed of coupled pieces of a board material. InFIGS. 5 to 7 showing bed operations, certain parts of the structure,such as side-member support frames 24R and 24L, have been omitted so asto illustrate the operations with clarity.

Among the side members 12Ra-12Rd/12La-12Ld, the side members 12Rc/12Lccorresponding to the upper-leg region of a care recipient's body havebox-shaped pockets with hollow space of approximately the samedimensions as the side members 12Rc/12Lc (see FIG. 8D showing a sideview of the bed). Fan-shaped members 13R/13L (13R not shown) are coupledto the edges of the side members 12Rd/12Ld corresponding to the carerecipient's lower-leg region. These members are normally housed in thepockets of the side members 12Rc/12Lc, respectively. Then, when the bedframe 10 is transformed into a flexion position, the fan-shaped members13R and 13L come out of the pockets to support the care recipient's kneeregion.

The adjustable stage 20 has a rectangular frame construction composed ofthe center beam 21A, side beams 21R and 21L, and two parallel end barsconnected to either end of the center beam 21A and side beams 21R and21L. On the side beams 21R and 21L, rollers 200, 201, 202, and 203 (theroller 203 not shown in FIG. 1, being behind the bed frame 10) aredisposed so as to slide in a y direction on roller slide bars 300 of thefixed stage 30, as indicated in FIG. 1.

Ladder-shaped side-member support frames 24R/24L are respectivelydisposed on the side beams 21R/21L of the adjustable stage 20. Each ofthe ladder-shaped side-member support frames 24R and 24L is composed oftwo bars 22R/22L and 23R/23L that run in the same direction as the sidebeam 21R/21L, and two connecting bars 231R/231L and 232R/232L. The bars23R and 23L have concave sections in the area where the side-membersupport frames 24R/24L meet the side members 12Rb/12Lb, so that the sidemembers 12Rb/12Lb fit in the space provided by the concave sections (seeFIG. 3 showing a plan view of the bed). Thus, the adjustable stage 20 isdesigned in such a way that the side members 12Rb/12Lb will notinterfere, in a thickness direction of the bed, with the side members12Ra/12La and the side members 12Rc/12Lc on either side of the sidemembers 12Rb/12Lb, when the bed frame 10 is transformed into the flexionposition. The bars 22R/22L are coupled respectively to the side beams21R/21L by couplers 236Ra/236La and 236Rb/236Lb, allowing the bars22R/22L to rotate freely through an axial direction while remainingsecured to the side beams 21R/21L. When the side-member support frames24R/24L are rotated on the axis of the rotating bars 22R/22L to aposition perpendicular to the horizontal bed surface (i.e. so as topoint in a z direction), the side members 12Ra-12Rd/12La-12Ld of the bedframe 10 are pushed up, thus enabling the right/left sides of the bedframe 10 to be raised.

Here, FIGS. 2A-2C are schematic sectional views of the bed showing theoperation of actuators in the vicinity of the adjustable stage 20 andthe upper-leg member 11 c of the bed frame 10. In addition to theactuators M1 and M2 used for transforming the bed frame 10,direct-acting actuators M3R and M3L are symmetrically disposed on theadjustable stage 20 to the left and right of the center beam 21A (i.e.in the y direction toward the coupling members 236Ra and 236La,respectively). The tips of shafts of the actuators M3R/M3L are coupledto L-shaped members 235R/235L fixed directly below the rotating bars22R/22L. According to this structure, the shafts of the actuatorsM3R/M3L extend, and thereby the L-shaped members 235R/235L and bars23R/23L are rotated on the axis of the rotating bars 22R/22L. Then, theside-member support frames 24R/24L are raised from the horizontal planeto a position perpendicular to the horizontal bed surface (FIGS.2A→2B→2C).

Stage bars 27R/27L are provided on the underside of the side beams21R/21L, and tightly fitted into stage-bar bearings 36R/36L (U-shapedcross-sectional) located to the side of the fixed stage 30. Within thesestage-bar bearings 36R and 36L, reverse L-shaped tabs are aligned in awidth direction of the bed. These tabs hook around the stage bars 27Rand 27L, and thereby the adjustable stage 20 is secured in a verticaldirection. When the adjustable stage 20 is tilted, the stage bar (i.e.either 27R or 27L) on the raised side is separated from thecorresponding stage-bar bearing (i.e. 36R or 36L).

FIG. 4 is a perspective view illustrating a structure of the fixed stage30. The fixed stage 30 includes a rectangular frame 31. A pair ofshorter ends of the frame 31 forms the roller slide bars 300 so that therollers 200-203 of the adjustable stage 20 travel back and forth onthem. Side beams 32R and 32L of the fixed stage 30 are slide-slotmembers (square-bracket cross-sectional), and are disposed such that theslide slots face one another. Into the side beams 32R/32L, the ends ofsupport arms 354R/354L and 356R/356L coupled respectively to thestage-bar bearings 36R/36L are tightly fitted so as to freely travelback and forth. Reverse L-shaped rotating arms 351R/351L and 352R/352Lcoupled at one end to the side beams 32R/32L are linked to the supportarms 354R/354L and 356R/356L, and horizontal links 353R/353L are coupledto the rotating arms 351R/351L and 352R/352L. Between the stage-barbearings 36R/36L and the horizontal links 353R/353L, actuators M4R/M4Lare respectively disposed at an angle. Herewith, parallelogrammechanisms 35R/35L, which are based on horizontal slide mechanisms, areformed on the right and left sides of the fixed stage 30. With theseparallelogram mechanisms 35R/35L, the rotating arms 351R/351L and352R/352L move in a circular motion centering on the points at whichthey are coupled to the side beams 32R/32L. One ends of the support arms354R/354L and 356R/356L travel back and forth on the inside of the sidebeams 32R/32L, while being regulated by the rotating arms 351R/351L and352R/352L. The support arms 354R/354L and 356R/356L oscillate in avertical direction, and thereby the adjustable stage 20, supported bythe stage-bar bearings 36R and 36L, and the bed frame 10 are able tomove vertically up and down from either or both the right and left sidesof the fixed stage 30. Therefore, the adjustable bed 2 can be elevatedeven in a small space as a consequence of space saving, while the use ofthe rollers 200-203 and the parallelogram mechanisms 35R and 35Lrealizes space saving even during postural change operations. By drivingone of parallelogram mechanisms 35R and 35L corresponding respectivelyto the side beams 32R and 32L, postural change from the supine tolateral position is achieved. On the other hand, a height adjustment(high/low) mechanism of the bed is realized when the parallelogrammechanisms 35R and 35L are driven simultaneously.

Note that the operations of the actuators M1, M2, M3R, and M3L arerespectively controlled by a motor driver and a CPU in a control unit(not shown). This allows the caregiver to use, for example, a controllerin hand to execute drive settings such as manual/automatic setting andprogram setting. In addition, the provision of a cord-attached cableremote control or an infrared wireless remote control enables settingsto be performed by the care recipient.

1.2 Operation of Adjustable Bed (Postural Change from Supine to LeftLateral)

An adjustable bed having the above structure is used with a mattressplaced on the bed frame 10. In a normal configuration, the coupledplatform 11 a-11 d and side members 12Ra-12Rd and 12La-12Ld are set tobe substantially horizontal as shown in FIG. 1.

When a user (here, for example, a caregiver) selects, from a menu, anitem relating, for example, to “postural change from the supine toleft-lateral position, in flexion position” via the controller and hasthis selection executed, firstly the actuator M3L attached to theadjustable stage 20 is operated to extend its shaft outward. The L-shape235L coupled to the tip of the shaft, and the bar 23L rotate on the axisof the rotating bar 22L, and the side-member support frame 24L risesfrom the horizontal position to a position vertical to the horizontalplane of the bed (FIGS. 2A→2B→2C showing actuator operations; FIG. 5showing side members 12La-12Ld in a vertically raised state; and FIG. 8Cshowing a side view of the bed in this state).

Next, the tips of shafts of the direct-acting actuators M1 and M2attached to the center beam 21A of the adjustable stage 20 extend out,pushing up the upper-body member 11 a and upper-leg member 11 c of thebed frame 10 from the underneath via the L-shaped couplers 211 and 212to place the care recipient in a flexion position with the upper bodyraised and the knees bent (FIG. 6 showing a perspective view of the bedin the flexion position; and FIGS. 8A→8B showing side views of the bedtransforming into this state). The side members 12La-12Ld also transformin conjunction with the coupled platform 11 a-11 d. At this point, thefun-shaped member 13L comes out from the pocket provided in the sidemember 12Lc to support part of the mattress and a bedding mattressaround the care recipient's knee region (FIGS. 8C→8D showing side viewsof the bed transforming into this state).

When the flexion position with the left side members raised is achievedaccording to the above operations, the actuator M4R on the right side ofthe fixed stage 30 operates to extend its shaft outward. As a result,the stage-bar bearing 36R and the horizontal link 353R separate from oneanother at an angle, the support arms 354R and 356R slide along theslide slot of the side beam 32R and rise up, and the parallelogrammechanism 35R operates. At this point, the support arms 354R and 356R(or 354L and 356L) raise the right side of the adjustable stage 20vertically upwards as a result of the circular movement of the rotatingarms 351R and 352R (or 351L and 352L). At the same time, the right sideof the adjustable stage 20 is raised to a higher position than the fixedstage 30, the roller 200-203 of the adjustable stage 20 roll on theroller slide bars 300, and the bed frame 10 tilts toward the side beam32L of the fixed stage 30, i.e., toward the left side of the bed (FIG. 7showing a perspective view of the bed being tilted). Here, a desirabletilt angle is in the range of, for example, approximately 30 degrees to70 degrees from the horizontal, one example being a tilt angle of 50degrees.

According to the above transformations of the bed frame 10, the postureof the care recipient is changed smoothly from the supine to the lateralposition while the body of the care recipient being supported by thecoupled platform 11 a-11 d and the side members 12La-12Ld after firstlyplaced in a supine flexion position with the upper body raised and kneesbent. Well-supported postural change that is similar to when a carerecipient is turned by the guiding hand of a caregiver is thus achieved.

According to the first embodiment, postural change of the care recipientis performed in a flexion position, which imposes the least burden onthe care recipient. As a result, the care recipient is able tocomfortably take an approach to postural change. Thus, it is promisingthat the conventional physical discomfort and psychological anxietyassociated with postural changes will ease. Furthermore, according tothe first embodiment, the caregiver is not required to performphysically hard working, manual procedures when changing the posture ofthe care recipient. Therefore, it is possible for even a caregiver withlittle experience to correctly perform postural change. By using theadjustable bed 2 of the first embodiment, the caregiver is thus betterable to focus on providing compassionate and attentive care.

1.3 Adjustable Bed Mattress (Having a Fixture) of the Present Invention

Here, an adjustable bed mattress 1 of the present invention is describedin detail. FIG. 9 shows an exemplary structure of the adjustable bed 2and an adjustable bed mattress used for the bed. The adjustable bedmattress 1 has a fixture 100 to be attached to the lower-back member 11b of the adjustable bed 2 corresponding to the hip region of a carerecipient's body, as shown in FIG. 9.

As shown in FIG. 10A, the fixture 100 has a structure in which a totalof four project portions 102, each having a T-shaped cross-sectionalconstruction, are disposed on a plate 101. The project portions 102 aremade of hard rubber, and tightly fitted into the interstices of the wiremesh covering the surface of the lower-back member 11 b of theadjustable bed 2 to fix the mattress onto the bed.

According to the mattress 1 having the fixture 100, when the bed isdriven and transformed into Gatch position (FIGS. 10B→10C), the head andfoot sides of the mattress 1 smoothly stretch while the mattress 1 iswell secured around the fixture 100 as shown in FIG. 10C. Herewith, theoccurrence of displacement of the mattress 1 (in the thrust direction)due to the adjustable bed operations can be effectively prevented whilea smooth mattress surface can be obtained due to the effect of themattress stretches. Note that the project portions 102 are detachablefrom the wire-mesh surface, which facilitates the replacement of themattress 1 and the maintenance of the adjustable bed 2.

In the case where the mattress 1 has relatively less stretches, thefixture 100 may be disposed on a part of the mattress 1 other than thepart facing the lower-back member 11 b. Thus, a location for setting thefixture 100 is not confined to the above, and furthermore multiplefixtures may be provided.

In addition, the fixture is not restricted to one having the abovestructure, and may alternatively have another structure (e.g. use of ahook and loop fastener on a section of the platform having a flatsurface) according to materials and a structure of the platform.

1.4 Related Matters

In the example given in the first embodiment above, the bed employs astructure that uses the parallelogram mechanisms. However, use of theadjustable bed mattress of the present invention is not limited to a bedhaving such a structure, and it is possible to apply the presentinvention also to adjustable beds having the following structures.

An adjustable bed shown in FIG. 11A has a structure in whichdirect-acting actuators are disposed vertically, and a set of sidemembers on the left or right is moved vertically up and down using aelevating mechanism. Herewith, the platform placed on an adjustablestage is tilted. With this adjustable bed, a pair of columnardirect-acting actuators is disposed within a rectangular fixed stage,and a bed frame supported by the adjustable stage is positioned on topof the actuators. The platform, as in the first embodiment, isconstructed as a coupled platform, which is formed by coupling togethera plurality of sections corresponding to the care recipient'supper-body, hip, upper-leg, and lower-leg regions. Among these, thesection corresponding to the hip region is secured to the adjustablestage having a frame construction. Provided on the underside of theplatform is a drive unit that includes an actuator mechanism for forminga flexion position.

The sets of side members are disposed on the columnar direct-actingactuators. Inside the side members, housing slots are formed. Here,housed in the housing slots are pullout walls, each of which formed bypartitioning a panel into sections along a longitudinal direction of thebed and coupling these sections with one another. The side members arecoupled to the adjustable stage supporting the platform via the pulloutwalls. The pullout walls are biased to a width direction of the housingslots by tension springs or the like, and are automatically housed inthe housing slots when a force pulling the pullout wall out of thehousing slots weakens.

According to an adjustable bed having the above structure, when the bedis driven, a flexion position is firstly formed with the coupledplatform, as shown in FIG. 11B. Subsequently, one of the columnardirect-acting actuators operates to lower a set of the side memberspositioned thereabove. In accordance with this operation, the adjustablestage is tilted, which brings the coupled platform down at an angle. Atthe lower side of the tilted adjustable stage, the pullout wall ispulled toward the coupled platform from the corresponding housing slotin a manner that the pullout wall is raised relative to the coupledplatform. That is, the pullout wall at the lower side hangs from thecoupled platform with the angle between the two narrowed. At the sametime, the side members are placed in a raised state relative to thecoupled platform. This achieves the effect of supporting the side of thecare recipient's body with the pullout wall while keeping the carerecipient in the flexion position. Thereby, postural change is performedin a favorable manner, as in the first embodiment.

FIGS. 12A-12F illustrate a structure of another adjustable bed.

The structure of this adjustable bed can be adopted by general-purposebeds. The adjustable bed is constituted by laying an air mattress formedfrom a plurality of airbags on a general-purpose bed. A characteristicof this adjustable bed is the use of an air pump to supply/discharge airindependently for each airbag via an air hose. The air hose has a valvewhose opening/closing motions, along with the air pump, are controlledby a control unit (not depicted), and thus, the inflation/deflation ofrespective airbags are individually controlled. The airbags are, as oneexample, partitioned into an upper body and hip portion (double layer),an upper and lower leg portion, and portions for right and left sides ofthe bed according to the joints of a care recipient's body.

An adjustable bed having the above structure is normally used with abedding mattress or the like placed over the air mattress. When posturalchange of the care recipient from the supine to the lateral position iscarried out, the airbags on both sides of the bed are firstly inflated(FIGS. 12A→12B). Next, the care recipient is placed in a flexionposition by tilting the airbag of upper body and hip portion in alongitudinal direction, and inflating the airbag of upper and lower legportion so as to form a knee break (FIGS. 12C and 12D). It is thenpossible to turn the care recipient to be in either the left or rightlateral position, while maintaining the flexion position, by deflatingthe airbag on either the left or right side and inflating the lower ofthe double layer airbags of upper body and hip portion (FIGS. 12E and12F).

Here shows an example using a general-purpose bed. However, theadjustable bed having the above structure has an advantage inportability, and therefore the bed can, in addition to being applied toa variety of general-purpose beds, also be laid directly on the floor(i.e. directly over tatami mats, carpet, or the like).

INDUSTRIAL APPLICABILITY

An adjustable bed mattress according to the present invention can beused as a mattress used for a nursing care bed or a reclining bed.

1. (canceled)
 2. A mattress to be laid on a platform of an adjustablebed having a transformable bed surface, wherein a mesh is formed on afront face of the platform, the front face forming at least part of thebed surface, a fixture that engages with the platform to secure themattress is disposed on a surface of the mattress facing the platform,and the fixture secures the mattress by tightly fitting into one or moreinterstices of the mesh.
 3. The mattress of claim 2, wherein the fixtureis detachable from the platform.
 4. The mattress of claim 2, wherein thefixture is disposed, on the surface of the mattress, in a part of themattress corresponding to a lower back region of a user lying on themattress.
 5. The mattress of claim 2, wherein the mattress is used withthe adjustable bed including, the platform of which the front face isflexible, a flex mechanism operable to flex the platform to form aflexion position that includes at least one of a sitting-up position anda knee break, and a tilt mechanism operable to tilt the front facelaterally, and both the flex mechanism and the tilt mechanism areoperable with the other mechanism in operating condition.
 6. Amattress-equipped adjustable bed having a transformable bed surface,comprising: a mattress of claim 2.